Seismic actuated shut-off valve

ABSTRACT

A shut-off valve which has a body (20) containing a seat 22 and a through passageway. A plug (32) is attached to a stem (36) which is spring loaded in a retracted position disposed above the valve in a housing 46. A severable link (70) is connected to the end of the stem (36) opposite the plug (32) with an arm (60) further extending the assembly terminating with a weight (68) on top. The arm (60) also contains a ball swivel (64) within a seat (66). Upon receiving external vibratory oscillation, such as a seismic shock wave, the weight (68) rotates axially about the swivel breaking the link (70) allowing the plug (32) attached to the stem (36) to be extended by the spring (58) into the valve seat (22) blocking flow of fluid through the passageway in the valve body.

TECHNICAL FIELD

This invention relates in general to fluid handling control regulated bychanging of position or inertia system and more specifically to a fluidshut-off valve actuated by a seismic shock wave fracturing a link,releasing a spring loaded plug into a valve seat.

BACKGROUND ART

Previously, mechanical valves for shutting off fluid flow due toearthquakes have used the principle of falling objects either filling avalve seat or triggering a spring loaded secondary apparatus.

Pazmany in U.S. Pat. No. 4,091,831 teaches such a device with a ballmounted on a pedestal falling and rolling onto a seat when motivated bya seismic shock. U.S. Pat. No. 3,747,616 issued to Lloyd also uses aball balanced on an inclined bar with a saddle similarly being unseatedand falling into the valve inlet orifice, restricting the fluid flow.

A ball is also utilized in U.S. Pat. No. 3,768,497 of Mueller, whereinthe ball falls onto a plate attached with a hinge to a closure diaphramshutting off the flow. Yamada in U.S. Pat. No. 3,878,858 teaches a ballon a pedestal falling to a secondary structure, triggering a valve, orthe like.

Greer in U.S. Pat. No. 4,116,209 employs a plumb valve body with agroove in a merging corner supported by a rib, which is dislodged byseismic vibrations falling into the port of the valve, effectivelyblocking the fluid flow. U.S. Pat. No. 3,965,917 of Speck applies a pairof reactant masses moving into an in-line interlocking position,releasing a hinged arm containing a seat disc accomplishing therestriction. Similarly, in U.S. Pat. No. 3,791,396 Nelson exercises abalanced weight falling from a support assembly, triggering a springloaded mechanism rotating a valve in a pipe line.

In each example of prior art, an object was dislodged from a stationaryelement, causing a reaction ultimately closing the valve, therefore, theaction is dependant upon the mechanical positioning or angulardisplacement of the member to produce the desired sensitivity to aseismic shock wave.

SUMMARY OF INVENTION

It is well known that the natural phenomenon of an earthquake cannotonly destroy man-made structures and endanger human life, but theaftermath of fire may sustain great property loss after the initialseismic vibrations have subsided. As building codes in earthquake proneareas have provided standards to protect the structures, few measureshave been legislated to prevent the aftermath of fire.

It is therefore, the primary object of the invention to provide a valvefor interrupting the flow of pressurized flammable or explosive fluidsinto residential, commercial or public structures. This includes naturalgas, butane, propane, fuel, oil and the like, in not only publicservice, but also storage tanks and auxillary facilities. If severedamage were to be inflicted, on any of the above, difficulty may beencountered in not only manually shutting off the flow, but even findingthe valve itself, or in the case of fire getting close enough toaccomplish the function.

An important object provides a valve that is not only functional insensing seismic vibrations, but is sensitive to the shock impact of apredetermined magnitude and repeatable within allowable tolerances. Thisprecludes nuisance trips and allows a different sensitivity to bepreselected for the area of use such as the general geographicallocation and if the valve were applied to rural or urban structures. Asan example, California uses a magnitude of 0.133 force of gravity asdesign criteria in earthquake prone areas. As prior art dictates the useof balls or falling objects for actuation, time may change thesensitivity of the setting, such as corrosion build-up on the seat oredge upon which the device rests or electrolysis in dissimilar metalseffecting edges and also operating mechanisms. The instant inventioneliminates this problem, as a fixed severable link is held in placelinearly between a stem and an arm and when subjected to a seismic shockwave a weight cantilevered above the link axially moves within pivotpoints breaking the link at a predetermined stress. When the link issevered the stem is attached to a plug that is spring loaded positivelyclosing the valve blocking the flow of fluid.

Another object allows the apparatus to be mounted in any position, asnormal gravitational influence is not requisite for operation. The valveplug is spring loaded and will be forced into the seat from any axiswhen the link is broken. This allows the valve to be installed in itspreferred vertical position without great sensitivity to its attitudewhere prior art is not afforded such latitude.

Still another object provides the use of materials not subjected todeterioration and enclosed within a housing that will protect theinternal mechanism from damage from falling matter, allowing the deviceto perform its function even under such adverse environmentalconditions.

Yet another object provides a manual opening rod that bypasses theoperation of the valve in the case of an accidental triggering of thespring loaded apparatus. This rod is screwed from the bottom of thevalve with normal hand tools relocating the plug from the seat to theloaded position compressing the piston spring and allowing normal fluidflow through the valve.

Finally a further object in another embodiment, best illustrated in FIG.3, includes a manually operated override that may trip the valve byexternal means, simply moving the weight, in the form of a ball, in anyhorizontal direction. This may be used in case of a fire or other damagenot preceded by an earthquake where it is desirable to shut-off thevalve to the structure quickly and without the use of tools. The exposedweight may be moved by hand, foot or in the event of surrounding heat,such as by a fire, may be actuated by a pole or throwing objectsbreaking the severable link.

These and other objects and advantages of the present invention willbecome apparent from the subsequent detailed description of thepreferred embodiment and the appended claims taken in conjunction withthe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevation view of the preferred embodiment partiallycut-away to expose the internal components.

FIG. 2 is a cross-sectional view of the preferred embodiment taken alonglines 2--2 of FIG. 1.

FIG. 3 is an elevation view of another embodiment partially cut-away toexpose the internal components.

FIG. 4 is a cross-sectional view of another embodiment taken along lines4--4 of FIG. 3.

FIG. 5 is an elevation view of yet another embodiment partially cut-awayto expose the internal components.

FIG. 6 is a cross-sectional view of yet another embodiment taken alonglines 6--6 of FIG. 5.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring now more particularly to the referenced characters of thedrawing, the invention employs a valve body 20 having an open passagewayfrom one side to the other. The inlet and outlet are identical and theflow of fluid may be from either direction. The body 20 has a minimumflow restriction through the passageway eliminating a pressure drop ofthe fluid while passing therethrough. The body 20 has a seat 22 locatedin the center in tapered form encompassing the entire central surface atany one given position. Means to attach the valve body 24 areincorporated in the inlet and outlet and may be any method of attachmentconvenient to fluid piping such as sweat joint, flare, compression,flange, weld with tapered pipe threads being preferred. A threadedopening 26 is located in the bottom of the body 20 in line with the seat22 and a bore 28 is incorporated in the opposed position. The bore 28further contains an internal thread 30 for attachment. The body 20 maybe of any material suitable for the application, such as bronze, steel,maleable iron, or the like, having structural integrity and thecapability of holding internal pressure. A piston plug 32 is locatedwithin the valve body 20 and is free to move slideably within theconfines of the walls and the valve seat 22. During operation the plug32 is positioned within the seat 22 closing-off the passageway blockingthe flow of fluid through the valve. The plug 32 is in the form of atruncated cone and has a bore 34 in the center through the entirelength. The material of the plug may be of any resilient or solidmaterial, such as rubber, neoprene, nylon, teflon, Buna N, steel, brass,bronze, maleable iron, or the like. Attached through this bore 34 in theplug 32 is a piston stem 36, best illustrated in FIG. 4. This stem isattached to the plug with a ring 38 on the top and a threaded fastener40 on the bottom. Another embodiment working equally well, shown in FIG.2, takes advantage of a threaded inset 41 in the plug 32 with thethreaded end of the stem 36 attaching directly to the plug eliminatingthe necessity of ring 38.

The upper end of the piston stem 36 employs a stem link jaw 42 in theform of a collet, or the like, rotatably reducing the size of a cavitydisposed within. When the jaw 42 is rotated, fingers are forced with acone effectively reducing the inside diameter. This element may use anysuitable configuration to maintain a cylindrical object in the internaldiameter with equal adaptivity. A stem spring flange 44 is attached tothe stem 36 distal-Proximate to either end and consists of a flat plateat right angles to the stem in arcuate fashion. This element ispermanently attached to the stem 36 by welding, brazing, soldering, orcompressingly upsetting the parent metal of the shaft, or the like. Thisdevice 44 provides a platform with the surface at right angles to thestem. The valve body 20 has attached at the internal threaded portion 30a spring housing 46 having an internal chamber defining an axial wallthat is open on each end. The lower end interfaces with the threads 30of the valve body and the upper end is similarly threaded 48 on theinterior surface for flange attaching. The housing 46 is hollow andprovides protection for apparatus contained within and acts as a spacer.In the lower centrally located portion of the housing 46 is, at least, apair of stem seals 50 contained within grooves. The seals 50 may be ofany configuration, however, "O"-ring type are preferred. The seals 50tightly surround the stem 36 creating a fluid tight seal restricting theflow of fluid from the valve body 20 to the spring housing 46 whileallowing the stem 36 to slide freely in a longitudinal direction.

An inertial weight flange 52 contains threaded attaching means 54 thatreversely correspond to the threads 48 of the spring housing 46. Thisflange 52 further contains a centrally located bore 56 that slideablyreceives the piston stem 36. When the flange 52 is attached to thehousing 46 a chamber is formed containing the stem 36 along with itsintegral flange 44. A piston spring 58 is disposed compressibly betweenthe stem spring flange 44 and the inertial weight flange 52. Thisarrangement forces compressibly the separation between the flangesurging the stem 36 in a downward direction into the valve body 20.

An inertial weight arm 60 in dowel shape is ultimately connected to thestem 36 and has attaching means in the form of a threaded fastener onthe top end for a weight mass and an arm link jaw 62 on the other end.This link jaw 62 contains a cavity and is similar in all respects to thestem link jaw 42. In close proximity to the jaw 62 is an arm ball swivel64 that is integral with the arm 6D. This swivel 64 is spherical inshape and allows the arm to swivel freely in an arc within the confinesof the apparatus. These confines are defined by an arm stabilizing frame66 in angular form in duplicate with an opposed pair of elementsdirected horizontally toward the ball swivel 64 on one end and theinertia weight flange 52 on the other. Each frame 66 is attached on oneend to the inertia weight flange 52 and the other to a pair of arm ballseats 67. The seats 67 surround a portion of the ball swivel 64 andallow axial movement to take place. The clearance between the ball 64and seat 67 is sufficient to allow movement without restriction, butbeing concave/convex surfaces containment is provided. An inertia weight68 is connected threadably to the arm 60 at the top end and provides amass for reactance to external shock and vibration. The weight 6B may bein any convenient shape and material, as only a gravitational force isrequired for proper operation of the arm.

A severable tension link 70 is located within and held in place bytension of the stem link jaw 42 and the arm link jaw 62. This connectionprovides a continuation of the arm 60 and the stem 36 being in directcommunication, also the spring 54 is in compression holding the plug 32above the valve seat 22. A manual opening rod 72 is threadably engagedinto the threaded opening 26 of the valve body 20 directly beneath theseat 22. An inertia weight housing 72 encompasses the weight 68, arm 60and associated elements and is threadably engaged into the flange 52.This housing is preferably cylindrical in shape with one open end,however, any convenient shape is acceptable.

In operation, the device is placed into a fluid line, as previouslydescribed, with the flow of fluid unrestricted. When subjected to earthvibrations in the form of seismic waves of sufficient magnitude, theinertia weight 68, being free to rotate about a pivot point in the ballswivel 64, creates a lateral force on the severable tension link 70. Thelink 70 is composed of a substance that is brittle in nature, such asglass, thermoplastic, metal, or the like, that when subjected to thispredetermined force shatters or fractures. This action allows thecompression spring 58 to release its energy, driving the stem 36downward with the accompanying plug 32. The plug 32 is then wedged intothe valve seat 22, causing a complete restriction to the flow of fluidthrough the valve 20 passageway. The balance between the force of thevibration and the brittleness of the link 70 determines the material tobe selected. Another consideration is its repeatability in its reactionto these forces.

To reset the valve, the manual opening rod 72 is rotated and through thethreaded action contacts the bottom of the piston plug 32 or stem 36pushing it upward against the pressure of the spring 58. This actionfrees the valve passageway without fluid leakage or the necessity ofopening the internal portion of the valve 20. The severable tension link70 may then be replaced by removing the inertia weight housing 72exposing the internal structure and rotating the jaws 42 and 62.

In another embodiment, best illustrated in FIGS. 3 and 4, the inertiaweight housing 72 applies the use of a resilient boot 74 disposed aboveand surrounding the arm 60 with the weight 68 being above and outside ofthe housing 72. The housing 72 is attached in like manner as above andserves the same purpose, except that the weight 68 is exposed above theboot allowing the weight 68 to be manually rotated actuating themechanism.

In another embodiment, pictorially shown in FIGS. 5 and 6, the inertiaweight 68, instead of being rotatably attached to the arm 60, issupported by a plurality of pivoted legs 76. The legs 76 are attached tothe weight 68 with pivot means 78 similarly the flange 52 contains pivotmeans 80, both being integral with their corresponding components. Thisarrangement allows lateral movement of the weight 68 in parallelogramfashion breaking the severable tension link 70 under the directed forceof the weight 68 when subjected to vibratory forces.

While the invention has been described in complete detail andpictorially shown in the accompanying drawings, it is not to be limitedto such details, since many changes and modifications may be in theinvention with departing from the spirit and the scope thereof. Hence,it is described to cover any and all modifications and forms which maycome within the language and scope of the appended claims.

We claim:
 1. A seismic actuated shut-off valve for fluid flow conduitscomprising:a. a valve body having an open passageway for passing fluidtherethrough having a centrally located plug seat, and a planar threadedopening; b. a piston plug positioned within said body slideablymaintained in alignment with said plug seat for blocking said passagewayto impede the flow of fluid; c. a piston stem fixed to said piston plugon the first end for urging said plug linearly into said plug seatmaintaining alignment thereof; d. a stem link jaw disposed on the secondend of said piston stem having a cavity with coarctation when rotatedtherewith; e. a stem spring flange fixed to said piston stem at rightangles in arcuate fashion between said piston plug and said stem linkjaw providing a platform with the superficies at right angles to saidpiston stem; f. a spring housing having an internal chamber defining anaxial wall, open on each end with the first end containing attachingmeans to embrace said valve body on the exterior and surround saidpiston stem distal-proximate the interior creating a chamber to enclosesaid piston stem along with said stem spring flange and the second endhaving flange attaching means; g. a plurality of stem seals containedwithin said spring housing urgingly embracing said stem and said housingrestricting the flow of fluid from said valve body to said springhousing while allowing said stem to slide longitudinally therethrough;h. an inertia weight flange containing attaching means to interface withsaid spring housing on said second open end, with said attaching means,and further containing a centrally located bore slideably receiving saidpiston stem providing a chamber with said stem extending therethrough;j. an inertia weight arm with inertia weight, link jaw and attachingmeans having a weight mass on the first end and a link jaw cavity on thesecond end with coarctation when rotated, being affixed pivotally tosaid inertia weight flange with attaching means extended therefrom,creating a lever arm allowing free movement as interacted with externalvibratory or shock wave forces; and, k. a severable tension linkdisposed between and compressibly engaged within said stem link jawcavity and said inertia weight link jaw cavity defining a continuousmember from said piston plug to said piston spring allowing reactance ofsaid inertia weight to axially rotate under the dominance of a seismicshock wave causing the link to structurally yield, fracture andseparate, thus permitting said piston spring to expand between said stemspring flange and said inertia weight flange linearly urging said pistonplug into said valve body plug seat obstructing the flow of fluidtherethrough.
 2. The invention, as defined in claim 1, furthercomprising: a manual opening rod having attachment means on one end withthreads integral with the longitudinal surface engaging said valve bodythreaded opening for urging said plug from said plug seat against thepiston spring compression when rotated therewith.
 3. The invention, inaccordance with claim 1, further comprising: an arm ball swivel integralwith said inertia weight arm, spherical in form, contiguous with saidinertia weight arm attaching means providing a swivel joint for said armallowing arcuate movement of the arm within the confines of saidattaching means.
 4. The inertia weight attaching means of the invention,as recited in claim 1 further comprising: an arm stabilizing framedisposed above said inertia weight flange and affixed thereto having acentrally located arm ball seat for containment of said arm ball swivelbeing juxtapositioned therewith in intimate fashion.
 5. The invention,in accordance with claim 4, further comprising: a weight housing beingdisposed above and surrounding said inertia weight, attaching means, armand tension link threadably affixed to said weight flange providing aprotective enclosure.
 6. The invention. in accordance with claim 4further comprising: a weight housing with a resilient boot beingdisposed above and surrounding said inertia weight attaching means, armand tension link threadably affixed to said weight flange with a portionof said arm protruding through the boot defining a protective enclosure.7. The inertia weight attaching means of the invention as recited inclaim 1, further comprising: a plurality of pivotal legs having clevismeans on each end, the first end pivotally attached to said weight andthe second end pivotally attached to said flange for lateral movement ofsaid weight in parallelogram fashion together with vertical support ofsaid weight allowing said severable tension link to separate under thelateral force of said weight when subjected to a seismic shock wave.